Effect of Incidental Findings Information on Lung Cancer Screening Intent: a Randomized Controlled Trial

BACKGROUND

The Centers for Medicare & Medicaid Services requires decision aid use for lung cancer screening (LCS) shared decision-making. However, it does not require information about incidental findings, a potential harm of screening.

OBJECTIVE

To assess the effect of incidental findings information in an LCS decision aid on screening intent as well as knowledge and valuing of screening benefits and harms.

DESIGN

Randomized controlled trial conducted online between July 16, 2020, and August 22, 2020.

PARTICIPANTS

Adults 55-80 years, eligible for LCS.

INTERVENTION

LCS video decision aid including information on incidental findings or a control video decision aid.

MAIN MEASURES

Intent to undergo LCS; knowledge regarding the benefit and harms of LCS using six knowledge questions; and valuing of six benefits and harms using rating (1-5 scale, 5 most important) and ranking (ranked 1-6) exercises.

KEY RESULTS

Of 427 eligible individuals approached, 348 (83.1%) completed the study (173 intervention, 175 control). Mean age was 64.5 years, 48.6% were male, 73.0% white, 76.3% with less than a college degree, and 64.1% with income < $50,000. There was no difference between the intervention and controls in percentage intending to pursue screening (70/173, 40.5% vs 73/175, 41.7%, diff 1.2%, 95% CI - 9.1 to 11.5%, p = 0.81). Intervention participants had a higher percentage of correct answers for the incidental findings knowledge than controls (164/173, 94.8% vs 129/175, 73.7%, 95% CI - 28.4 to - 13.8%, p < 0.01). Incidental findings had the fifth highest mean importance rating (4.0 ± 1.1) and the third highest mean ranking (3.6 ± 1.5). There was no difference in mean rating or ranking of incidental findings between intervention and control groups (rating 4.0 vs 3.9, diff 0.1, 95% CI - 0.2, 0.3, p = 0.51; ranking 3.6 vs 3.6, diff 0.02, 95% CI - 0.3, 0.3, p = 0.89).

CONCLUSIONS

Incidental findings information in a LCS decision aid did not affect LCS intent, but it resulted in more informed individuals regarding these findings. In formulating screening preferences, incidental findings were less important than other benefits and harms.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04432753.

What is the effect of a decision aid on knowledge, values and preferences for lung cancer screening? An online pre-post study

OBJECTIVE

To examine if a decision aid improves knowledge of lung cancer screening benefits and harms and which benefits and harms are most valued.

DESIGN

Pre-post study.

SETTING

Online.

PARTICIPANTS

219 current or former (quit within the previous 15 years) smokers ages 55-80 with at least 30 pack-years of smoking.

INTERVENTION

Lung cancer screening video decision aid.

MAIN MEASURES

Screening knowledge tested by 10 pre-post questions and value of benefits and harms (reducing chance of death from lung cancer, risk of being diagnosed, false positives, biopsies, complications of biopsies and out-of-pocket costs) assessed through rating (1-5 scale) and ranking (top three ranked).

RESULTS

Mean age was 64.7±6.1, 42.5% were male, 75.4% white, 48.4% married, 28.9% with less than a college degree and 67.6% with income <US$50 000. Knowledge improved postdecision aid (pre 2.8±1.8 vs post 5.8±2.3, diff +3.0, 95% CI 2.7 to 3.3; p<0.001). For values, reducing the chance of death from lung cancer was rated and ranked highest overall (rating 4.3±1.0; 59.4% ranked first). Among harms, avoiding complications (3.7±1.3) and out-of-pocket costs (3.7±1.2) rated highest. Thirty-four per cent ranked one of four harms highest: avoiding costs 13.2%, false positives 7.3%, biopsies 7.3%, complications 5.9%. Screening intent was balanced (1-4 scale; 1-not likely 21.0%, 4-very likely 26.9%). Those 'not likely' to screen had greater improvement in pre-post knowledge scores and more frequently ranked a harm first than those 'very likely' to screen (pre-post diff:+3.5 vs +2.6, diff +0.9; 95% CI 0.1 to 1.8; p=0.023; one of four harms ranked first: 28.4% vs 11.3%, p<0.001).

CONCLUSIONS

Our decision aid increased lung cancer screening knowledge among a diverse sample of screen-eligible respondents. Although a majority valued 'reducing the chance of death from lung cancer' highest, a substantial proportion identified harms as most important. Knowledge improvement and ranking harms highest were associated with lower intention to screen.

Dietary Patterns Derived from UK Supermarket Transaction Data with Nutrient and Socioeconomic Profiles

Poor diet is a leading cause of death in the United Kingdom (UK) and around the world. Methods to collect quality dietary information at scale for population research are time consuming, expensive and biased. Novel data sources offer potential to overcome these challenges and better understand population dietary patterns. In this research we will use 12 months of supermarket sales transaction data, from 2016, for primary shoppers residing in the Yorkshire and Humber region of the UK (n = 299,260), to identify dietary patterns and profile these according to their nutrient composition and the sociodemographic characteristics of the consumer purchasing with these patterns. Results identified seven dietary purchase patterns that we named: Fruity; Meat alternatives; Carnivores; Hydrators; Afternoon tea; Beer and wine lovers; and Sweet tooth. On average the daily energy intake of loyalty card holders -who may buy as an individual or for a household- is less than the adult reference intake, but this varies according to dietary purchase pattern. In general loyalty card holders meet the recommended salt intake, do not purchase enough carbohydrates, and purchase too much fat and protein, but not enough fibre. The dietary purchase pattern containing the highest amount of fibre (as an indicator of healthiness) is bought by the least deprived customers and the pattern with lowest fibre by the most deprived. In conclusion, supermarket sales data offer significant potential for understanding population dietary patterns.

Screening for Lung Cancer With Low-Dose Computed Tomography: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Lung cancer is the leading cause of cancer-related death in the US.

OBJECTIVE

To review the evidence on screening for lung cancer with low-dose computed tomography (LDCT) to inform the US Preventive Services Task Force (USPSTF).

DATA SOURCES

MEDLINE, Cochrane Library, and trial registries through May 2019; references; experts; and literature surveillance through November 20, 2020.

STUDY SELECTION

English-language studies of screening with LDCT, accuracy of LDCT, risk prediction models, or treatment for early-stage lung cancer.

DATA EXTRACTION AND SYNTHESIS

Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings. Data were not pooled because of heterogeneity of populations and screening protocols.

MAIN OUTCOMES AND MEASURES

Lung cancer incidence, lung cancer mortality, all-cause mortality, test accuracy, and harms.

RESULTS

This review included 223 publications. Seven randomized clinical trials (RCTs) (N = 86 486) evaluated lung cancer screening with LDCT; the National Lung Screening Trial (NLST, N = 53 454) and Nederlands-Leuvens Longkanker Screenings Onderzoek (NELSON, N = 15 792) were the largest RCTs. Participants were more likely to benefit than the US screening-eligible population (eg, based on life expectancy). The NLST found a reduction in lung cancer mortality (incidence rate ratio [IRR], 0.85 [95% CI, 0.75-0.96]; number needed to screen [NNS] to prevent 1 lung cancer death, 323 over 6.5 years of follow-up) with 3 rounds of annual LDCT screening compared with chest radiograph for high-risk current and former smokers aged 55 to 74 years. NELSON found a reduction in lung cancer mortality (IRR, 0.75 [95% CI, 0.61-0.90]; NNS to prevent 1 lung cancer death of 130 over 10 years of follow-up) with 4 rounds of LDCT screening with increasing intervals compared with no screening for high-risk current and former smokers aged 50 to 74 years. Harms of screening included radiation-induced cancer, false-positive results leading to unnecessary tests and invasive procedures, overdiagnosis, incidental findings, and increases in distress. For every 1000 persons screened in the NLST, false-positive results led to 17 invasive procedures (number needed to harm, 59) and fewer than 1 person having a major complication. Overdiagnosis estimates varied greatly (0%-67% chance that a lung cancer was overdiagnosed). Incidental findings were common, and estimates varied widely (4.4%-40.7% of persons screened).

CONCLUSIONS AND RELEVANCE

Screening high-risk persons with LDCT can reduce lung cancer mortality but also causes false-positive results leading to unnecessary tests and invasive procedures, overdiagnosis, incidental findings, increases in distress, and, rarely, radiation-induced cancers. Most studies reviewed did not use current nodule evaluation protocols, which might reduce false-positive results and invasive procedures for false-positive results.

Assessment of Lung Cancer Screening Program Websites

IMPORTANCE

The US Preventive Services Task Force recommends that individuals at high risk for lung cancer consider benefits and harms before pursuing lung cancer screening. Medical centers develop websites for their lung cancer screening programs, but to date little is known about the websites' portrayal of benefits and harms or what next steps they recommend for individuals considering screening.

OBJECTIVE

To assess the presentation of potential benefits and harms and recommended next steps on lung cancer screening program websites.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional content analysis of 162 lung cancer screening program websites of academic medical centers (n = 81) and state-matched community medical centers (n = 81) that were randomly selected from American College of Radiology lung cancer screening-designated centers was conducted. The study was performed from December 1, 2018, to January 31, 2019.

MAIN OUTCOMES AND MEASURES

Website presentation of screening-associated benefits and harms was the primary outcome. Benefit was defined as any description related to the potential reduction in lung cancer mortality. Harms were based on the US Preventive Services Task Force recommendations and included false positives, false negatives, overdiagnosis, radiation exposure, and incidental findings. The secondary outcome was next steps that are recommended by websites.

RESULTS

Overall, the 162 lung cancer screening program websites described the potential benefits more frequently than they described any potential harms (159 [98%] vs 78 [48%], P < .01). False-positive findings were the most frequently reported (72 [44%]) potential harm. Community centers were less likely than academic centers to report any potential harm (32 [40%] vs 46 [57%], P = .03), potential harm from radiation (20 [25%] vs 35 [43%], P = .01), and overdiagnosis (0% vs 11 [14%], P < .01). One hundred nineteen websites (73%) did not explicitly recommend that individuals personally consider the potential benefits and harms of screening; community centers were less likely than academic centers to give this recommendation (15 [19%] vs 28 [35%], P = .02). Most institutions (157 [97%]) listed follow-up steps for screening, but few institutions (35 [22%]) recommended that individuals discuss benefits and harms with a health care professional.

CONCLUSIONS AND RELEVANCE

Information on public-facing websites of US lung cancer screening programs appears to lack balance with respect to portrayal of potential benefits and harms of screening. Important harms, such as overdiagnosis, were commonly ignored in the sites evaluated, and most of the centers did not explicitly guide individuals toward a guideline-recommended, shared decision-making discussion of harms and benefits.

Clinical Yield of a Molecular Diagnostic Panel for Enteric Pathogens in Adult Outpatients With Diarrhea and Validation of Guidelines-Based Criteria for Testing

Background

Molecular diagnostic panels for enteric pathogens offer increased sensitivity and reduced turnaround time. However, many pathogen detections do not change clinical management, and the cost is substantial.

Methods

We performed a retrospective chart review of adult outpatients with diarrhea at the University of Virginia who had samples tested by the FilmArray Gastrointestinal Panel (BioFire Diagnostics, Salt Lake City, UT) to identify the clinical yield and to validate the clinical criteria for testing recommended in the 2017 Infectious Diseases Society of America (IDSA) guidelines.

Results

We analyzed 629 tests sent from adult outpatients with diarrhea between March 23, 2015, and July 18, 2016. A pathogen was detected in 127 of 629 specimens (20.2%). The most common pathogens were enteropathogenic Escherichia coli (47, 7.5%), norovirus (24, 3.8%), enteroaggregative E. coli (14, 2.2%), Campylobacter (9, 1.4%), and Salmonella (9; 1.4%). The clinical yield of testing was low, with antimicrobial treatment clearly indicated for only 18 subjects (2.9%) and any change in clinical management indicated for 33 subjects (5.2%). Following the clinical criteria for diagnostic testing from the 2017 IDSA guidelines, which suggest diagnostic testing for patients with fever, abdominal pain, blood in stool, or an immunocompromising condition, would have reduced testing by 32.3% without significantly reducing the clinical yield (sensitivity, 97.0%; 95% confidence interval [CI], 84.2%-99.9%; negative predictive value, 99.5%; 95% CI, 97.3%-100.0%).

Conclusions

The clinical yield of molecular diagnostic testing in this population was low. Compliance with IDSA guidelines in adult outpatients with diarrhea could reduce testing by approximately one-third.

A mass-market appraisal of the English housing rental market using a diverse range of modelling techniques

INTRODUCTION

Mass appraisals in the rental housing market are far less common than those in the sales market. However, there is evidence for substantial growth in the rental market and this lack of insight hampers commercial organisations and local and national governments in understanding this market.

CASE DESCRIPTION

This case study uses data that are supplied from a property listings web site and are unique in their scale, with over 1.2 million rental property listings available over a 2 year period. The data is analysed in a large data institute using generalised linear regression, machine learning and a pseudo practitioner based approach.

DISCUSSION AND EVALUATION

The study should be seen as a practical guide for property professionals and academics wishing to undertake such appraisals and looking for guidance on the best methods to use. It also provides insight into the property characteristics which most influence rental listing price.

CONCLUSIONS

From the regression analysis, attributes that increase the rental listing price are: the number of rooms in the property, proximity to central London and to railway stations, being located in more affluent neighbourhoods and being close to local amenities and better performing schools. Of the machine learning algorithms used, the two tree based approaches were seen to outperform the regression based approaches. In terms of a simple measure of the median appraisal error, a practitioner based approach is seen to outperform the modelling approaches. A practical finding is that the application of sophisticated machine learning algorithms to big data is still a challenge for modern desktop PCs.

High-Grade Myxoid Liposarcoma (Round Cell Variant) in a Dog

A 10-year-old, neutered male, Basset hound had a 26 × 21 × 21 cm infiltrative mass on the left abdominal wall that did not extend into the peritoneal cavity based on radiographs and abdominal computed tomography. Cytological examination revealed moderate numbers of neoplastic round cells, which frequently contained numerous round, clear, cytoplasmic vacuoles. Histologically, the tumour was composed of two morphologically distinct cell populations forming a continuum of heterogeneously differentiated cells. The primary spindle-shaped population formed streams with abundant, lightly eosinophilic, alcian blue-positive, myxoid matrix. The second population was arranged in sheets and had a round cell appearance. Scattered within both populations were neoplastic cells containing variably sized, intracytoplasmic, osmium tetroxide-positive vacuoles (lipid). Multifocal large pools of mucin formed pseudocysts, and numerous small capillaries were present throughout the neoplasm. According to the current World Health Organization veterinary classification of liposarcomas, this neoplasm had morphological features of both the myxoid and pleomorphic variants of liposarcoma; however, it was analogous to the recently defined high-grade myxoid liposarcoma in man. Myxoid liposarcoma with round cells has not been described previously in dogs. This case highlights the need to potentially re-evaluate the current classification of liposarcomas in animals.

Rhodococcus equi Infections in Dogs

Five cases of Rhodococcus equi infection in dogs were identified from 2003 to 2014. Three of the dogs had severe, internal lesions attributable to R. equi that have not been previously described: endophthalmitis, endocarditis, and suppurative pleuropneumonia. Isolates from 4 of the dogs were analyzed by polymerase chain reaction for Rhodococcus virulence-associated plasmid (vap) genes. One isolate was vapA-positive, 2 lacked a virulence plasmid, and 1 carried the novel vapN-associated plasmid (pVAPN) recently characterized in bovine isolates. The pVAPN plasmid has not been described in isolates cultured from companion animals. Four of the dogs either were receiving immunosuppressive drugs or had endocrinopathies. R. equi has the potential to cause significant infections in dogs, and immunocompromised animals should be considered at risk for infection.

Intra-ventral tegmental area microinjections of urotensin II modulate the effects of cocaine

Although the peptide urotensin II (UII) has well studied direct actions on the cardiovascular system, the UII receptor (UIIR) is expressed by neurons of the hindbrain. Specifically, the UIIR is expressed by the cholinergic neurons of the laterodorsal tegmentum (LDTg) and the pedunculopontine tegmentum (PPTg). These neurons send axons to the ventral tegmental area (VTA), for which the PPTg and LDTg are the sole source of acetylcholine. Therefore, it was hypothesized that UIIR activation within the VTA would modulate reward-related behaviors, such as cocaine-induced drug seeking. Intra-VTA microinjections of UII at high concentrations (1 nmole) established conditioned place preference (CPP), but also blocked cocaine-mediated CPP (10 mg/kg). When rats received systemic sub-effectual doses of cocaine (7.5 mg/kg) with intra-VTA injections of 1 or 10 pmole of UII CPP was formed. Furthermore, the second endogenous ligand for the UIIR, urotensin II-related peptide, had the same effect at the 10 pmole dose. The effects of low doses of UII were blocked by pretreatment with the UIIR antagonist SB657510. Furthermore, it was found that intra-VTA UII (10 pmole) further increased cocaine-mediated (7.5 mg/kg) rises in electrically evoked dopamine in the nucleus accumbens. Our study has found that activation of VTA-resident UIIR produces observable behavioral changes in rats, and that UIIR is able to modulate the effects of cocaine. In addition, it was found that UIIR activation within the VTA can potentiate cocaine-mediated neurochemical effects. Therefore, the coincident activation of the UII-system and cocaine administration may increase the liability for drug taking behavior.

Administration of 100% oxygen does not hasten resolution of symptomatic spontaneous pneumothorax in neonates

OBJECTIVE

To compare the effectiveness of 100% oxygen therapy vs oxygen treatment with targeted pulse oximetry in the management of symptomatic small to moderate spontaneous pneumothorax (SP). In total, 100% oxygen treatment for SP has been a common practice in neonatology, albeit there is little evidence to validate its efficacy.

STUDY DESIGN

A retrospective chart review of 83 neonatal records with the diagnosis of pneumothorax was conducted. Infants <35 weeks gestation, those with large pneumothoraces requiring chest tube drainage and/or ventilatory support were excluded. Data gathered included demographics, vital signs, treatment information and clinical indicators of resolution of symptoms.

RESULT

In total, 45 neonates with SP were included in the study. Groups were similar for gestational age, birth weight, Apgar scores, gravidity, parity, gender, race, pneumothorax size and location. Patients in the 100% oxygen therapy group received a significantly longer oxygen treatment (21.3 vs 8 h, P < 0.001), required longer intravenous fluid treatment (48.6 ± 29.9 vs 31.3 ± 18.8 h, P = 0.03) and were delayed in reaching full feeds (44.1 ± 25.7 vs 29.5 ± 18.8 h, P = 0.03) compared with the oxygen-targeted treatment group. Time to first oral feeding, time to resolution of tachypnea and length of stay were similar in both groups.

CONCLUSION

There are no clinically significant advantages to using 100% oxygen in the treatment of symptomatic small to moderate SP. In fact, it may result in longer exposure to unnecessary oxygen treatment and toxicity. Oxygen should be reserved for those who are hypoxic and adjusted to comply with accepted saturation levels in neonates.

Sub regional estimates of morbidities in the English elderly population

This study focuses on identifying the future trends and spatial concentrations of morbidities in the English elderly population. The morbidities to be estimated are: coronary heart disease; strokes; diabetes; cancer; respiratory illnesses and arthritis in the 60 year and older household residential population. The technique used is a spatial microsimulation of the elderly population of local authorities in England using data from the 2001 Census and the English Longitudinal Study of Ageing. The longitudinal nature of the microsimulated population is then used to estimate the morbidity prevalences for local authorities in 2010/2011. With this knowledge, planners will be able to focus the available health and care resources in those areas with greatest need. For most of these morbidities, there is evidence of a strong correlation between the type of authority and the estimated prevalence rates.

Fusion of diphtheria toxin and urotensin II produces a neurotoxin selective for cholinergic neurons in the rat mesopontine tegmentum

Urotensin II is a neuropeptide first isolated from fish and later found in mammals: where it has potent cardiovascular, endocrine and behavioral effects. In rat brain the urotensin II receptor (UII-R) is predominately expressed in the cholinergic neurons of the pedunculopontine (PPTg) and laterodorsal tegmental nuclei. Typically, the function of the PPTg has been examined using excitotoxins, destroying both cholinergic and non-cholinergic neurons, which confounds interpretation. We took advantage of UII-R's unique expression profile, by combining UII with diphtheria toxin, to engineer a toxin specific for cholinergic neurons of the PPTg. In vitro, two different toxin constructs were shown to selectively activate UII-R (average EC50 approximately 30 nmol/L; calcium mobility assay) and to be 10,000-fold more toxic to UII-R expressing CHO cells, than wildtype cells (average LD50 approximately 2 nmol/L; cell viability). In vivo, pressure injection into the PPTg of rats, resulted in specific loss of choline transporter and NADPH diaphorase positive neurons known to express the UII-R. The lesions developed over time, resulting in the loss of over 80% of cholinergic neurons at 21 days, with little damage to surrounding neurons. This is the first highly selective molecular tool for the depletion of mesopontine cholinergic neurons. The toxin will help to functionally dissect the pedunculopontine and laterodorsal tegmental nuclei, and advance the understanding of the functions of these structures.

The urotensin II receptor is expressed in the cholinergic mesopontine tegmentum of the rat

Urotensin II (UII) is a peptide known to be a potent vasoconstrictor. The urotensin II receptor (UII-R) is expressed not only in peripheral tissues but also in the brain of rodents. As a basis for studies of UII central nervous system actions, UII-R localization in the rat brain was analyzed by in situ hybridization and by in situ binding. UII-R mRNA was found in the mesopontine tegmental area colocalizing with choline acetyltransferase. Binding sites were detected throughout the brain with the highest levels found in the pedunculopontine tegmental area, the lateral dorsal tegmental area, and the lateral septal, medial habenular, and interpeduncular nuclei. The majority of these brain nuclei are sites of axonal termination originating from the mesopontine areas, suggesting that UII-R is a presynaptic receptor. This distribution of UII-R in the cholinergic mesopontine area indicates that the UII system may be involved in sensory-motor integration and perhaps in central nervous system blood flow.

Hyperexpression in Escherichia coli, purification, and characterization of the metallo-beta-lactamase of Bacillus cereus 5/B/6

We used site-directed mutagenesis to introduce both a NdeI restriction endonuclease site and an initiator codon at the junction of the leader and structural gene sequences of the metallo-beta-lactamase of Bacillus cereus 5/B/6. This construct allowed us to clone just the beta-lactamase structural gene sequence into an Escherichia coli expression vector. E. coli cells were transformed with the recombinant plasmid, the B. cereus beta-lactamase was expressed, and these E. coli cells were disrupted by sonic oscillation. When the resultant suspensions were clarified by ultracentrifugation, the B. cereus beta-lactamase represented 15% of the total protein in the supernatant. Subsequent gel filtration and ion-exchange chromatography allowed the first reported purification to homogeneity of the B. cereus beta-lactamase from E. coli with an 87% recovery and an overall yield of 17 mg of enzyme per liter of cell culture. The electrophoretic mobilities of the enzyme expressed in and purified from E. coli and the enzyme purified directly from B. cereus were identical in both native and sodium dodecyl sulfate gel electrophoreses. As with the B. cereus enzyme, Km and Vmax (using cephalosporin C as substrate) for the enzyme purified from E. coli were 0.39 mM and 1333 units/mg protein, respectively. Likewise, the Co(II)-reconstituted enzyme purified from E. coli, which retained 29% of the activity of the Zn(II) enzyme, had electronic absorption spectra with maxima at 347, 551, 617, and 646 nm with extinction coefficients of 900, 250, 173, and 150 M-1 cm-1, respectively.

Yeast tRNATrp genes with anticodons corresponding to UAA and UGA nonsense codons

Naturally occurring suppressor mutants derived from tRNATrp genes have never been identified in S. cerevisiae. Oligonucleotide-directed mutagenesis was used to generate potential ochre and opal suppressors from a cloned tRNATrp gene. In vitro transcription analyses show the ochre suppressor form of the gene, TRPO, accumulates precursors and tRNA in amounts comparable to the parent. The opal suppressor, TRPOP, accumulates 4-5 fold less tRNA. Both forms of the gene are processed and spliced in vitro to produce tRNAs with the expected base sequences. The altered genes were subcloned into yeast vectors and introduced into yeast strains carrying a variety of amber, ochre, and opal mutations. When introduced on a CEN vector, neither ochre nor opal suppressor forms show suppressor activity. Deletion of the CEN region from the clones increases the copy number to 10-20/cell. The opal suppressor form shows moderate suppressor activity when the gene is introduced on this vector, however, the ochre suppressor form exhibits no detectable biological activity regardless of gene copy number. Northern blot analyses of the steady state levels of tRNATrp in cells containing the high copy-number clones reveal 20-100% increases in the abundance of tRNATrp.

Helping managers to manage: work schedules of field-workers in rural Bangladesh

The Maternal-Child Health/Family Planning (MCH/FP) Extension Project in Bangladesh identifies and examines barriers to implementation of the national MCH/FP program, and determines strategies to overcome them. This study analyzes field-workers' ability to carry out more tasks than they do presently, and how their performance might be improved when additional field-workers are hired. In two experimental subdistricts, researchers observed the work of family welfare assistants (FWAs), the female family planning field-workers, to determine the duration and frequency of their home visits with village women and the content of their exchanges. While many factors influence the FWA's work, researchers found that the preplanned monthly work schedules could be manipulated relatively easily to improve duration and frequency of program contact with village women. With more time available to spend with women, the potential to improve the quality of services is enhanced.

Regulation of the expression of tissue inhibitor of metalloproteinases and collagenase by retinoids and glucocorticoids in human fibroblasts

The regulation of the expression of interstitial collagenase and tissue inhibitor of metalloproteinases (TIMP) was examined in response to both retinoid compounds and glucocorticoids. Effective retinoids induced a dose-dependent, specific increase in the production of TIMP of approximately two- to threefold by monolayer cultures of human fibroblasts derived from various tissues, while simultaneously causing a decrease in collagenase secretion of similar magnitude. These effects were apparent by 8-12 h in culture and disappeared within 24 h after the withdrawal of retinoid compounds. The retinoid effect on TIMP production was mediated via an increased biosynthesis of new inhibitor protein. Similarly, increased steady state levels of TIMP messenger RNA (mRNA) accompanied by decreased quantities of collagenase mRNA were demonstrated, suggesting transcriptional control of the retinoid action. The data suggest that retinoids co-regulate the expression of collagenase and TIMP, and do so in an inverse manner. Dexamethasone caused a dose-dependent, specific decrease in collagenase production without altering the biosynthesis of TIMP. These findings were paralleled by a marked reduction in collagenase mRNA, without any accompanying change in TIMP mRNA. Therefore, TIMP and collagenase expression appear to be independently modulated by glucocorticoids.

Human fibroblast collagenase: glycosylation and tissue-specific levels of enzyme synthesis

Human skin fibroblasts secrete collagenase as two proenzyme forms (57 and 52 kDa). The minor (57-kDa) proenzyme form is the result of a partial posttranslational modification of the major (52-kDa) proenzyme through the addition of N-linked complex oligosaccharides. Human endothelial cells as well as fibroblasts from human colon, cornea, gingiva, and lung also secrete collagenase in two forms indistinguishable from those of the skin fibroblast enzyme. In vitro tissue culture studies have shown that the level of constitutive synthesis of this fibroblast-type interstitial collagenase is tissue specific, varies widely, and correlates with the steady-state level of a single collagenase-specific mRNA of 2.5 kilobases. The tumor promoter, phorbol 12-myristate 13-acetate, apparently blocks the control of collagenase synthesis resulting in a similarly high level of collagenase expression (approximately equal to 3-7 micrograms of collagenase per 10(6) cells per 24 hr) in all examined cells. The constitutive level of synthesis of a 28-kDa collagenase inhibitor does not correlate with that of the enzyme. Phorbol 12-myristate 13-acetate stimulates the production of this inhibitor that in turn modulates the activity of collagenase in the conditioned media. As a result, the apparent activity of the enzyme present in the medium does not accurately reflect the rate of its synthesis and secretion.

Sex, contraception and parenthood: experience and attitudes among urban black young men

Eighty-seven percent of black adolescent males attending an inner-city junior high school and senior high school in Baltimore report that they have had sexual intercourse. Eighty percent of the sexually experienced teenagers have used a contraceptive method--and 60 percent used one at last intercourse. Contraceptive practice is characterized by heavy reliance on male methods: Of those using a method at last intercourse, 41 percent relied on the condom; 15 percent, on withdrawal; and 14 percent, on a combination of male and female methods. Use of female methods alone (mostly the pill) accounted for 28 percent of contraceptive practice at last intercourse. Nine-tenths of the teenagers have heard of the pill and condom, but far smaller majorities have heard of the IUD and diaphragm (about three-fifths each). In general, this population regards the condom as comparable in effectiveness to the pill. More than two-fifths of those recognizing these methods believe the pill--and the condom--to be "very good" at preventing pregnancy, and one-fifth believe that about the IUD and diaphragm. Nearly four in 10 mistakenly believe that they need a parent's permission to attend a birth control clinic, while slightly more than half think they need permission to buy nonprescription contraceptives in a drugstore . Although nearly nine in 10 respondents recognize that boys share a responsibility for preventing pregnancy when they have sex, more than half are willing to tolerate unprotected coitus. Most wish to delay parenthood until their early 20s, but many of these adolescents appear to hold attitudes conducive to out-of- wedlock conception.(ABSTRACT TRUNCATED AT 250 WORDS)

Monoclonal autoantibody directed toward histone and capable of inducing LE cell formation

LE cell formation is one feature of systemic lupus erythematosus exhibited by virtually all mice of the NZB/NZW strain and is the result of accumulation of antibodies directed against components of cell nuclei. A hybrid cell line which produces antibodies capable of inducing LE cell formation in vitro has been isolated in a hybridoma fusion using the splenocytes of unimmunized NZB/NZW mice. These monoclonal autoantibodies provide an intense staining of the chromatin in cells of a number of divergent species and tissues. They bind strongly to the histone rich (2 M NaCl) fraction of extracted, isolated nuclei. Further analyses using the antibodies in immune precipitations and in antibody labeling of capillary blots on nitrocellulose sheets of calf thymus histone demonstrate that the antibodies are directed against histones and are capable of reacting with H1, H2a, H2b, H3, and H4 histones individually. In contrast to human autoantibodies with histone specificity, no cross-reactivity of this monoclonal autoantibody with the lymphocyte surface could be detected by either immunofluorescence or immunoelectron microscopy.

Regional blood flow in the domestic fowl immediately following chronic acceleration

In order to examine the effects of chronic low G acceleration on blood flow distribution and cardiac output, chickens (N=10) were centrifuged at +2Gz for 30-61 d. Controls (N=12) were not centrifuged. The animals were anesthetized with sodium pentobarbital after removal from the centrifuge and surgically prepared in order to measure cardiac output and regional blood flows by the reference sample method with 85Sr labeled microspheres (15 +/- 5 mum diam.). Both brachial arteries were cannulated to withdraw timed, paired blood samples at a known rate. The chest was opened and a cannula inserted into the left ventricle for administration of microspheres. Tissue samples were taken after completion of experimental procedures and their radioactivity was determined. The cardiac outputs in the two groups were not significantly different. Regional blood flows to the kidney, eyes, and skeletal muscle were significantly increased in the animals subjected to chronic +2Gz. While the mechanism by which these increases in blood flow occurred is not known, results indicate that chronic exposure to hyperdynamic gravitational fields can alter circulatory dynamics. We conclude that the cardiovascular system is directly involved in the process of adaptation to chronic positive acceleration.

California physician's professional image of therapists

The purpose of this study was to identify the attitudes of California physicians toward the professional image of physical therapists and to determine the influence of several independent variables on that image. A three-part questionnaire was used to survey the sample of physicians. The first two sections contained attitudinal statements based on criteria representing degrees of professionalism; the third section contained questions on demographic variables. The results indicated that, although the majority of responding physicians viewed physical therapists as possessing all of the criteria denoting professionalism, there was relatively less agreement with the two criteria representing the highest degrees of professionalism-evaluative skills and autonomy of judgment. None of the independent variables influenced physicians' professional image of physical therapists except physician specialty area, in which family practitioners held a significantly higher professional image of physical therapists than did neurosurgeons and orthopedists. The authors suggest further study of other factors that may affect physicians' professional image of physical therapists as well as recommend steps that may be taken to improve the professional image of physical therapists.

Environmental nitroso compounds: reaction of nitrite with creatine and creatinine

Creatine reacts with nitrite under acid conditions to produce first sarcosine and then N-nitrososarcosine, which is a weak carcinogen in the rat. Creatinine reacts with acidified nitrite to produce either creatinine-5-oxime or 1-methylhydantoin-5-oxime, depending on reaction conditions. The toxicity and environmental significance of these compounds is not yet known.